The present technology relates to a microparticle sorting apparatus and a delay time determination method in the microparticle sorting apparatus. More specifically, the present technology relates to a microparticle sorting apparatus or the like which automatically determines the delay time.
In the related art, there is a microparticle sorting apparatus (for example, a flow cytometer) which optically, electrically, or magnetically detects the characteristics of microparticles such as cells, then separates and collects only the microparticles which have predetermined characteristics.
In cell separation in a flow cytometer, first, a droplet stream (a laminar flow of a sample fluid containing cells and a sheath fluid) is generated from an orifice formed in the flow cell, the fluid stream is made into droplets by applying oscillation to the orifice, and a charge is applied to the droplets. Furthermore, the movement direction of the droplets containing the cells discharged from the orifice is electrically controlled and the target cells having the desired characteristics and the other non-target cells are collected in separate collection containers.
For example, Japanese Unexamined Patent Application Publication No. 2010-190680 discloses, as a microchip-type flow cytometer, “a microparticle sorting apparatus including: a microchip on which a flow path through which a fluid containing microparticles flows, and an orifice which discharges a fluid which flows through a flow path to a space outside of the chip are installed; an oscillating element for making a fluid into droplets in the orifice and discharging them; an electrical charging means for applying a charge to the discharged droplets; an optical detection means for detecting the optical characteristics of the microparticles flowing though the flow path; an electrode couple installed opposing one another to interpose the moving droplets; and two or more containers which collect the droplets which passed between the opposing electrodes”.
In addition, Japanese Unexamined Patent Application Publication (Translation of PCT Application) No. 2007-532874 discloses a method in which control is performed on the operation of a flow cytometer which is capable of confirming whether or not the droplets have been sorted into an intended flow path by disposing auxiliary lighting and a detection unit in the position at which the droplets break off from the fluid (hereinafter, referred to as the break-off point). By ascertaining the break-off point in this manner, it is possible to ascertain the delay time from when the microparticles, which are cells or the like, are detected until the droplets containing the cells or the like reach the break-off point, and it is possible to apply a charge to the droplets containing the microparticles which are detected based on the delay time.